Recent studies have suggested that the angioplasty procedure is superior to medication alone for relieving angina in selected patients. The angioplasty procedure has been shown to reduce symptoms in patients with coronory artery disease as well as in patients with peripheral vascular disease as well as being useful adjunct in patients experiencing an acute myocardial infarction.
During angioplasty and related procedures, a guidewire is inserted into an artery and maneuvered to the site of the stenosis. Since the guidewire is relatively fine and difficult to grip between the fingers, a device called a "torquer" is affixed to the wire and used to twist the wire to negotiate the various turns and branches in the coronary arteries. As might be expected, the angioplasty procedure requires precision and intense continuous concentration on the part of the surgeon.
Current torquers suffer from various disadvantages the most notable of which is that since the torquer must be manually locked onto the wire, repositioning the torquer from a locked position at one place on the wire to a locked position at another place on the wire is a two-handed operation. Conventional torquers employ a locking nut portion, which, when turned in one direction causes the torquer to lock onto the wire; and which, when turned in the opposite direction releases the torquer so that it may freely slide along the wire. Unlocking this type of torquer, moving it along the wire, and locking it in place is a tow-handed operation requiring the surgeon's full attention and generally necessitates a period of time when non-visualization of the patents coronary anatomy occurs. Hence, the physician's attention is directed away from fluoroscopy video monitoring equipment and hemodynamic monitoring equipment.
Since it is often a lengthy and arduous process to properly position the wire in the patient's artery, a loss of registration or position while the surgeon repositions the torquer on the wire is costly in the sense of loss of the physician's time, and also potentially painful, uncomfortable and subject to acute vascular complications in patients undergoing the procedure.
Another tool for steering an angioplasty guide wire includes a body of resilient material with a slit in which the guide wire is received. Therefore, the tool can be attached to the wire from the side. An outer sleeve encircles the resilient body and may be used to compress the resilient body holding the slit closed to grip the wire tightly. This tool, however, suffers from the same problem as conventional torquers: repositioning the tool on the wire requires pulling the wire out of the slit, repositioning the tool on the wire, and finally pressing the wire back into the slit. As delineated above, such a time consuming, two-handed operation is adverse to an efficient angioplasty procedure.
Finally, when these conventional torquers are released from the wire, a process which may be performed two to three times to reposition the torquer during the angioplasty procedure, the turning motion used to separate the torquer from the wire is transmitted to the wire itself causing the end of the wire to turn in the artery and even jerk slightly. Hence, a loss of registration can occur further interfering with the expeditious performance of the angioplasty procedure and possibly causing procedure lengthening and patient discomfort.